Various industries would benefit from a system which accurately and cost-effectively identifies an interface between two different materials. For example, in the downhole drilling and completions industry, tanks and vessels are utilized for storing a plurality of materials such as treatment and stimulation fluids that must be pumped downhole. The identification of the aforementioned interface can be used for example to determine and monitor the level of the stored materials in these vessels and tanks, i.e., the interface between formed between the stored material and air. Boreholes themselves represent a structure in which the interfaces between various materials, e.g., between water-bearing and oil-bearing zones, are often desired to be determined. In the above-noted and other applications, new and alternate systems for determining the levels of materials or interfaces therebetween are desired.